Pupil, substances causing dilation

A male patient is brought to the emergency department (HD) following ingestion of an unknown substance. He is found to have an elevated temperature, hot and flushed skin, dilated pupils, and tachycardia. Of the following, which would most likely cause these findings ... 

Although atropine is a known antidote against several toxic substances, its overdose can cause severe poisoning. As with other tropane alkaloids, atropine competitively blocks muscarinic acetylcholine receptor sites. This results in dilation of the pupil of the eye (mydriatic effect), dryness of the mucous membranes, especially of the mouth, and inhibition of activity of sweat glands (parasympatholytic action). At toxic doses, it causes palpitation, speech disturbance. 

From the earliest times chemicals have been used in the treatment of disease. The substances that were first used as drugs are natural products such as in the leaves, branches, and roots of plants. Man (perhaps more often women than men) slowly learned by trial and error that the ingestion of certain plants had certain effects. It was discovered, for example, that ingestion of certain plants of the family Solanaceae causes mydriasis, the dilation of the pupil of the eye. One of these plants is named//opr/ belladonna. Belladonna means beautiful woman and it was, and perhaps still is, thought that women with large pupils are more beautiful than those with small pupils. 

Notably, pseudoephedrine is a diastereomer of ephedrine and considerably racemic ephedrine (dl-ephedrine) has not been found naturally, however, it is prepared synthetically and is inactive for commercial purposes. Ephedrine and pseudoephedrine are completely stable compounds under changing temperature conditions, but they are quite unstable when exposed to sunlight or in the presence of oxygen pressure [2]. The unique molecular structure of ephedrine causes its different stereoisomers to be valuable for pharmaceutical applications such as nasal decongestant, pupil dilator, bronchodilator, and central nervous system stimulant. Ephedrine is a sympathomimetic substance and the principle mechanism of ephedrine activity is its influence, by enhancing the activity of noradren-alin, on post-synaptic a- and (3-receptors in the nervous system. Stimulation of a 1-adrenergic receptors produces contraction of vascular smooth muscle. 

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